How to find the highest value in an array

All arrays have a built-in method called max(), which returns the highest item in the array. This comes with a default implementation if the elements of the array conform to Comparable: it will simply compare all items until it finds the one that compares highest.

For example, this code puts 5 into the max constant:

let numbers = [1, 2, 3, 4, 5]
let max = numbers.max()

Note: because max() can be called on an empty array, it returns an optional – you need to check and unwrap it yourself.